(a) Field of the Invention
The present invention relates to a color-filter substrate and a liquid crystal display, and more particularly, to a color-filter substrate and a liquid crystal display in which each pixel has two different transmittances.
(b) Description of the Related Art
FIG. 1 partially shows a schematic cross-section of a conventional liquid crystal display. Referring to FIG. 1, the liquid crystal display 90 includes a color filter substrate 912, an array substrate 914 and a liquid crystal layer 916. The color filter substrate 912 and the array substrate 914 are opposite each other. The liquid crystal layer 916 is interposed between the substrates 912 and 914, and has negative dielectric anisotropy so that the liquid crystal molecules are in a vertical alignment when a voltage is not applied thereto. Pixel electrodes 922 and switch devices (not shown) are formed on a transparent substrate 928 of the array substrate 914. The switch devices may be a thin-film transistor, or the like. In the color filter substrate 912, a color filter 930 are formed on a transparent substrate 926, and a common electrode 924 is formed on the color filter 930. The color filter 930 includes a black matrix layer 934 and filter traces 932.
When a user watches at a large viewing angle a conventional liquid crystal display having a vertical alignment structure, he may observe a color washout phenomenon in which the skin color tends to appear in pale blue or white. Appling technologies, such as dual gate line, dual data line (T-T type), common voltage swing, partial voltage of thin-film transistor or capacitance coupling (C-C type), to a pixel being divided into a plurality of areas may be solutions to reduce the color washout. Each of these approaches has drawbacks. For example, the technologies of dual data line and common voltage swing require additional ICs and components, which includes the manufacturing time and material cost. The technologies of partial voltage of thin-film transistor or capacitance coupling may reduce the color washout without using any additional ICs; however it reduces the aperture ratio due to the additional thin-film transistor. In addition, the technology of capacitance coupling forms self-coupled capacitance due to the floating electrodes, which causes serious image-sticking.
When a conventional liquid crystal display is touched by a finger of a user, the touch gets the liquid crystal molecules out of order, and causes fingerprint mura. In the conventional liquid crystal display, it takes a relatively long recovering time for the liquid crystal molecules to recover and turn to the direction of the electric field. Increasing the density of photo spacers or forming a patterned transparent electrode on the array substrate 914 may be a solution to the fingerprint mura. However, the former increases the manufacturing time and cost as a result of slowing down the speed of injecting the liquid crystal; the latter reduces the aperture ratio.